[PATCH v3 05/10] KVM: MMU: introduce slot_handle_level_range() and its helpers

Xiao Guangrong
2015-05-13T06:46:18Z

There are several places walking all rmaps for the memslot so that
introduce common functions to cleanup the code

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
---
arch/x86/kvm/mmu.c | 69 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 69 insertions(+)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index df403b3..62ac4e0 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -4453,6 +4453,75 @@ void kvm_mmu_setup(struct kvm_vcpu *vcpu)
init_kvm_mmu(vcpu);
}

+/* The return value indicates if tlb flush on all vcpus is needed. */
+typedef bool (*slot_level_handler) (struct kvm *kvm, unsigned long *rmap);
+
+/* The caller should hold mmu-lock before calling this function. */
+static bool
+slot_handle_level_range(struct kvm *kvm, struct kvm_memory_slot *memslot,
+ slot_level_handler fn, int start_level, int end_level,
+ gfn_t start_gfn, gfn_t end_gfn, bool lock_flush_tlb)
+{
+ struct slot_rmap_walk_iterator iterator;
+ bool flush = false;
+
+ for_each_slot_rmap_range(memslot, start_level, end_level, start_gfn,
+ end_gfn, &iterator) {
+ if (iterator.rmap)
+ flush |= fn(kvm, iterator.rmap);
+
+ if (need_resched() || spin_needbreak(&kvm->mmu_lock)) {
+ if (flush && lock_flush_tlb) {
+ kvm_flush_remote_tlbs(kvm);
+ flush = false;
+ }
+ cond_resched_lock(&kvm->mmu_lock);
+ }
+ }
+
+ if (flush && lock_flush_tlb) {
+ kvm_flush_remote_tlbs(kvm);
+ flush = false;
+ }
+
+ return flush;
+}
+
+static bool
+slot_handle_level(struct kvm *kvm, struct kvm_memory_slot *memslot,
+ slot_level_handler fn, int start_level, int end_level,
+ bool lock_flush_tlb)
+{
+ return slot_handle_level_range(kvm, memslot, fn, start_level,
+ end_level, memslot->base_gfn,
+ memslot->base_gfn + memslot->npages - 1,
+ lock_flush_tlb);
+}
+
+static bool
+slot_handle_all_level(struct kvm *kvm, struct kvm_memory_slot *memslot,
+ slot_level_handler fn, bool lock_flush_tlb)
+{
+ return slot_handle_level(kvm, memslot, fn, PT_PAGE_TABLE_LEVEL,
+ PT_MAX_HUGEPAGE_LEVEL, lock_flush_tlb);
+}
+
+static bool
+slot_handle_large_level(struct kvm *kvm, struct kvm_memory_slot *memslot,
+ slot_level_handler fn, bool lock_flush_tlb)
+{
+ return slot_handle_level(kvm, memslot, fn, PT_PAGE_TABLE_LEVEL + 1,
+ PT_MAX_HUGEPAGE_LEVEL, lock_flush_tlb);
+}
+
+static bool
+slot_handle_leaf(struct kvm *kvm, struct kvm_memory_slot *memslot,
+ slot_level_handler fn, bool lock_flush_tlb)
+{
+ return slot_handle_level(kvm, memslot, fn, PT_PAGE_TABLE_LEVEL,
+ PT_PAGE_TABLE_LEVEL, lock_flush_tlb);
+}
+
void kvm_mmu_slot_remove_write_access(struct kvm *kvm,
struct kvm_memory_slot *memslot)
{
--
2.1.0